Administrative Code of 1987
Section 13. Vacancy in Office of the President. - In case of death, permanent disability, removal from office, or resignation of the President, the Vice-President shall become the President to serve the unexpired term. In case of death, permanent disability, removal from office, or resignation of both the President and Vice-President, the President of the Senate or, in case of his inability, the Speaker of the House of Representatives, shall then act as President until the President or Vice-President shall have been elected and qualified.
The Congress shall, by law, provide who shall serve as President in case of death, permanent disability, or resignation of the Acting President. He shall serve until the President or Vice-President shall have been elected and qualified, and be subject to the same restrictions of powers and disqualifications as the Acting President.